Present work machines, such as skid steer loaders and the like, utilize various implements, such as hydraulically operated trencher assembly. Typically, the trencher assembly has a digging boom connected to the machine for pivotal movement. A digging chain is rotatably mounted on the boom and driven for digging in the ground, and an auger is provided which disperses the spoil that is dug during the trenching operation to the sides of the trench.
A problem with known trencher assemblies relates to the complexity of the drive trains for the digging chain and spoil dispersing auger. Generally, the drive assembly for the chain and auger are separate and include a plurality of sprockets, belts, chains, drive shafts, and the like. The drive assemblies are complex and, in some instances, uncovered which permits dirt and debris to enter between the moving parts thereby causing jamming or failure of the various external bearings. Therefore, there is a need for an improved drive train assembly for the digging chain and spoil dispersing auger of the trencher assembly which is compact and fully covered to prevent the entry of debris and the like into the moving parts.
An approach for improving the drive train assembly is disclosed in U.S. Pat. No. 4,327,508 issued to Stephen A. Youngers on May 4, 1982. This patent utilizes a trenching machine with a totally enclosed drive train assembly for the digging chain drive sprocket and spoil dispersing auger. The drive train assembly is totally enclosed and includes a hydraulic motor, a rotatable drive sprocket-hub subassembly, a planetary gearbox, and a boom lift casting. The planetary gearbox and hydraulic motor are mounted on opposite sides of the boom lift casting, and are drivingly interconnected by a drive shaft that passes through the casting. The digging chain drive sprocket subassembly is rotatably mounted by bearings within a hub on the boom lift casting adjacent the planetary gearbox. The digging chain drive sprocket assembly includes a sprocket that is connected to the planetary gearbox through the hub. Additionally, an auger is connected to the gearbox opposite the digging chain drive sprocket assembly. Therefore, the digging chain drive sprocket assembly and auger are driven in unison by the hydraulic motor through the rotation of the gearbox. The separation of the hydraulic motor from the planetary gearbox increase the complexity of this design. This is most evident by the separate hub and sprocket of the digging chain drive sprocket subassembly. The hub includes the bearings to drive the digging chain drive sprocket and the sprocket is interconnected with the hub to drive a respective digging chain. The usage of a separate sprocket and hub and, further, the usage of the bearing within the hub increase the components required to drive the trencher. Therefore, it is desired that a totally enclosed drive train assembly be provided with a simple design that reduces components. Further, the design should directly drive both the digging chain drive sprocket assembly and auger from the motor to increase the compactness of the design.
The present invention is directed to overcoming the problems as set forth above.